1. Field of the Invention
The present invention relates to a feeder device for a receiving apparatus and, more particularly, to a feeder device for feeding a medium to a device, the feeder device having an adjustably flexible feed gate apparatus, and associated method.
2. Description of Related Art
A printer device such as, for example, a printer as described herein, typically includes a feeder for supplying media, such as individual cards, to the printer, a print engine which includes a transport mechanism for transporting the card through the printer and a printing mechanism for printing on the individual cards, and an exit or output hopper for receiving the printed cards. Further, the feeder generally comprises a card hopper for receiving the stack of cards to be fed, in addition to a drive mechanism for feeding the cards to the print engine. A gate at the exit of the feeder, otherwise known as the outlet opening, can include a separation mechanism for separating individual cards, usually an end card, from the stack in order to feed only one card to the print engine at each feed cycle.
Such a card feeder may be used on other card processing systems, such as a patch lamination system, a magnetic card or smart card encoding system, or the like. The drive system generates the driving force for the end card and the separation mechanism generates a separation force on the stack so as to allow the end card to be separated therefrom. With such a card feeder system, a general intent is to provide a driving force on the end card that is greater than the separation force imparted on the stack under many conditions that can exist in the card feeder. The separation force exerted by the separation mechanism on the stack typically has to be greater than a sticking force that can exist between the end card and the remainder of the cards in the stack. This sticking force may be related to, for example, electrostatic discharge (“ESD”) between cards, cut or folded card edges, the weight of the stack on the end card, the thickness of the cards in the stack, or other factors or combinations thereof.
In order to address these concerns in a card feeder, a compromise often must be achieved between the separator mechanism, which exerts the separating force on the stack that must be greater than the sticking force between the stack and the end card, and the drive system, which must provide a driving force greater than the separating force, regardless of the type, thickness, condition, and quantity of the cards in the stack. As such, early card feeder devices implemented a fixed gate having a fixed dimension outlet opening generally corresponding to the thickness of a single card. However, such a configuration is generally effective only for the particular card thickness, and that effectiveness may be limited in instances of, for example, card thickness variation within the stack, or warped cards.
One further development was to provide a gate allowing for height adjustment of the outlet opening in correspondence with the thickness of the card to be fed. In such instances, the gate was provided with a movable blade, such as a cam-operated movable blade. However, the effectiveness of the movable blade configuration was also limited in instances of, for example, card thickness variation within the stack, or warped cards.
Other instances of such a card feeder include a flexible blade affixed to the gate so as to allow the outlet opening to vary in dimension to better accommodate the thickness of the card being fed. The flexible blade more readily accommodates card thickness variations within the stack or warped cards. However, the flexible blade may often be optimized for a particular card thickness or a narrow range of card thicknesses, and thus may not be applicable or effective for different card thicknesses or card thicknesses outside the optimal thickness range.
A further example of a card feeder is disclosed in U.S. Pat. No. 6,536,758 to Meier et al. The Meier '758 patent describes a feeder having movable gate with a flexible blade, wherein the gate/blade assembly is adjustable to accommodate various card thicknesses. That is, the cards are fed through an outlet opening in a hopper wall and the flexible blade reduces a height of the outlet opening to less than the thickness of the end card. As a card is passed through the outlet opening, the card contacts the flexible blade and the blade flexes in response. The control gate is movable to adjust the height of the outlet opening, the height corresponding to a particular contact between the card and the blade, where the contact is related to the separating force. Thus, for a particular gate position, the card being fed through the outlet opening may experience a different separating force depending on card thickness.
That is, if the card thickness increases over the card thickness corresponding to the position of the gate, a larger portion of the blade contacts the card fed through the outlet opening. The increased contact with the blade thereby increases the separating force and, depending on the thickness of the card, the separating force can become greater than the driving force provided by the card drive. Such an occurrence may undesirably cause card misfeeds. On the other hand, if the card thickness decreases compared to the card thickness corresponding to the position of the gate, a smaller portion of the blade contacts the card fed through the outlet opening. The thinner card thereby experiences a decreased separating force due to the decreased contact with the blade and, as a result, the separating force can become lesser than the sticking force between cards. Such an occurrence may undesirably cause double-feeding of the cards.
While the Meier '758 patent allows the gate to be moved so as to accommodate varying card thicknesses by varying the separating force, the range of card thicknesses that can be fed at each gate position may be limited or a large number of closely spaced gate positions may be necessary for the card feeder to be effective over a large range of card thicknesses. This limitation may be at least partially due to the particular configuration of the flexible blade, which may have a flexibility only be suitable for narrow range of card thicknesses. That is, the gate adjustment is related to the contact between the blade and the card fed through the outlet opening, which is generally effective for a range of card thicknesses, while the blade flexibility is selected to provide a particular range of separating force. As such, if a particular card has a thickness toward a high end of the thickness range, the blade may not provide a suitable separating force for the card greater than the sticking force between cards, while a card thickness toward a low end of the thickness range may experience a separating force from the blade that exceeds the driving force from the card drive.
Thus, there exists a need for a feeder device capable of supplying media, such as cards, stock, paper, cardboard, etc. to a print engine in a secure, reliable, and efficient manner, without such undesirable occurrences as, for example, multi-card feeding or misfeeds, if the hopper is not empty. Such a feeder device should desirably provide effective media feeding for different types of material, for different thicknesses, and for media throughout the stack of media, from the first media unit to last media unit in the stack.